This graph from AV-TEST's website shows a sharp growth of Android Malware since January, 2011. According to their report, the number of Android apps has grown from 100,000 in July 2010 to 450,000 today. WIth a very fast market growth and increasing popularity, it is no wonder why the amount of malware is increasing.

If you use the market (or Play Store as it is now called) to install apps, you should definitely look into installing one of these malware applications. One thing that I would definitely like to see is how each application performs and its battery consumption. That would help me to decide which to use.

Just a note, I wasn't able to find F-Secure's app in the Play Store. I went to mobile.f-secure.com to download it.